Lathe



R. C. MOORE May 31, 1932.

LATHE Filed Sept. 25. 1929 2 Sheets-Sheet 1 i j so'that it isverydifficult to obtain the proper' thrust thereby. VVhenth'e' friction surfaces are oily, it ispractically impossibleto eXertr suffieient force on the, spindle to cause the VPatented May 31, 1932 f fm-60,684

RICHARD'- Mocna, or rriiEsvILLn; oHIo, nssnoivonro 'TH- neon .miimrrnorunrne COMPANY, or PAINESVILLE, oHIo, A CORPORATION or! o'rno i :LATH' z *Appii'eaon med sep'mberza', rezerw serial 1%; 894,897;

of general applieationto l'athes of 'all kinds, certain of these features are also of p'artiou-f. l-ar V adaptaibility to veneer lathes, and' es-' peeially the arrangelnents for moving the dogging spindle thereof toward the log, to'` bring the dogging' spindle into drifvizng engagement with the end of the log. i

Power means have been provided a Vfriction drive or olutoh interposed-therein to prevent d'amage due to tardy manual release' of* the power drive. The coeficioient of frietion for such cl'utohes or drives vares with thel condition of the friotion surfaoes,

Chuck to engage the log sufi'iciently tight for proper Cutting.

i of the s-pi-ndle by the entire power 'of the main drive of the lathe. produced are enormous,. and' lathe frames have been broken when expe'dient has;

' been employed.

i dogging spindfle into: engagement withfthe It is,v therefore, an object of' the present invention to provide a means for movlngthe log,vto` exertt'h'e proper 'thrust thereon without entailing the diflieulties p'oin't'e'df 'out above.

'It isV a further-*obj'ect of the invention to' provide a positive drive for exerting the proper thrust' on the spi-ndle,` thus avoiding the disadvantagesof thefriction olutch.

Another object is'to' exert a predeterniined:

maximum thrust on the;4 spindle for mov'- ifng it into engagement with a log. f

Still another' object ofthe inventio'n: isto prevent the power drive means for moving the' spindle toward the: log, and exertlng a thrust thereonz exceeding a predeterminedz Under this condition-,V` a a bralre has been providedto hold the dogging' nut stationary thus eifeeting the rn'ovement` rl`he stresses thusv` VC'ampiisma, in the'specifie ezfitoaiment for the i' infventi'on.` disclfosed'. her'eizn, Aby 'positifvel'y driving' the dogging spindlef toward the' log;k from ind'uetion motor ofthe' squirrel Cage-T type',: havingia high: torqfue' rotor adapted' to rOth'er'fobjects" an'd f' atures of.` i be appa'rent asf the following description procee'd's, as taken in'` oonju'r-ieti'onl with the aocompanying drawings',in which.- for` this i purpose, but under manual control, and withl 'Fig '1 is al vertieat lreair 'view' of vlia'the' i orthefoperatorls side of the'1athe;,* I

, Fig.*2' is an end vi'ewof the doggihg', end M ofthe1athe;`l ,o

, Fig. 3 is a ourvepl'otte'dv with torquefv ab? soifssasz and' speed ordinates, showing a ooi'n-`v parison of torquespeedcharaoteristics' of ind'uctionmotors' Withl various rotors.

Fig. 4 is a' fragmentary topplan viewfof' i the ci'rcuitbrea'ker switch' aotuated. bythe' olutoh lever';v and' w: g Fi-g. 'is a'V diagram o'fgtheiwiri'ngz of the independent motorsi i '1 The presentinvention is illustrated invcone nection with a type of veneer Cutting lathe heretof'ore disclosed.` Apa-ilr of standards 10 and: l-lga're eonnectedftogether by spacers` 12.1 oThestand'ards-l 10- a'nd 1-1 suitabl'y sup'-4 port a pair of horizontal'l'y movable s'pindles,1 the dogg-ing spind'le beingi-ndicatedby 113i' andv the ta'i-lspind'le being ind-iea-te'd bvV 14.'

The front. or; log sid'eof .the standards: 10? f 11 is provided withza transversev recess 11'5' whiehg reoeivesand: supports' a; spir'idl'e.`l sleeVe-f 1.6; The spindles 13'and1-4'are' veX-teil'iorlysorew-thre'aded? andv extendthrough the? sleeve 16;?the latter beingipro'videdxY Withai dependingtongue .or spli'no;` 178 engageable.y with a: ooolperating groove or' key'way 129"- ex.-- tending throughoutthe length: of thefspindle.

Tof'i-Inpartaxial movement to thespind'le'. i 13! toithrustfit into' engagement with the end* ofV a log',;a\ spindl'e drrving sl'eeve'V 20 inter-'ion'VV lyvv screwL-threaded engagesz the' sorew'threadsof the spind'leV and is: rotatably mounted w'ithp.` in a looking'membe'r 21':` which isl s'uitabl-y w w' V spin'dle: lfhas securely -mounted uponfitsfree end a sprocket wheel 22 which is adapted to rotate the spindle drv'ing sleeve 20 to cause longitudinalmovement of the spindle 13 in either direction depepnding upon the direction,

of rotation of the sprocketlwhe'el. i It will, therefore, be seen that to reciprocate the spindle 13vtoward or away from the spindle 14,

the sprocket'wheel 22 is rotated in the proper 'direction The spindle driving sleeve 20,`

whic hfis'associated with the spindle 14, is provided with a 'hand-wheel 23.V

Apair of bull gears 29 arepositioned with-` in suitable slots in the .face of each standard and securely supported upon o the .spindle sleeves 16; These bull gears 29 are keyed to thespindle sleeves 16 so that upon rotation imparted to the bullv gears, the logis rotated,

i keyed thereto a pair ofipinions 33 which engage withthebul-l gears 29. It Will beV readilyV understood/froni the foregoing description then thatv the log isl rotated 'While the V Veneer .is being cut therefrom by causing rotation of the main drive shaft 31 and that the re'ciprocation of. the spindles 13 .and 14 is independent thereof.V o VThe sprocket wh'el 22 is actuated by a Chain 34 having a positive drive fromv a reversible motor 36 connected in a suitable circuit. TheV direction of rotation of thearmature is Controlled by push button switch 38. VVhen'one button on the switchV 38 vis depressed, the motor 36 is actuated to move the (logging spindle in one fdirection, and When the other button of the same switch isrdepressed,.thev spindle is'mo'ved in the opposite direction.

V`A slidably mounted carriage 39`supports v'the Veneer Cutting knife for -movementto- Ward and away vfrom the log. Threaded shafts whichlmove the carriage are driven by suitable gear-ing froma carriage feed shaft 49 drivenl bychain'51'from motor'50.. The

motor 50 :is connected in'a circuit in seriesV with a push button'switch 52 mounted adjacentl the switch. 38. Shaft 49 .is also Connected to the main driveshaftl by suitable gearing v and clutch niechanism 54. i The Wiring diagram of vFig5 showsthe circuits .for the dogging. spindle motor and the carriage feed i motor. .The dogging spindle motor 36 has three con'ductorwires 64, and 66.' lAtriple knife switch 67 normally biased open'has its terminals connected to conductor wires 68,

69 and 7 0, the wires 68V and 70 being connected to'one side of the main line while the Wire 69 'is connected to the other side of themain line: The switch 67 :is closed by energizinga i solenoid 71 connected'by'a Wire 72 to the con- 74 is connected between the out push button and the conductor Wire 70. To reverse the direction of rotation of the motor 36, the wires 75, 76 and 77 are suitably connected as vshown in Fig. 5 to the conductor wires 66, 64

and 65, respectively, andto a pluralityV of contact fingers.. p triple'knife'switchz78 is. normally biased open and connected by wires 79, 80 and 81 to the conductor wires 70, 69

w and 68, respectively'. The switch 78 is closed: 'by energizing of solenoid 82 connected by a I wire 83 to the in push button, and connected by a wirel 84 to the Wire 69 leading to the main line. The in push button is connected Vto the return Wire 7 4.

The Wiring for the circuit of the carriage feed motoris the7 same Vas the wirlng of 'the doggingsspindle motor with one ezrception 'A Circuit breaker switch 61'81s vemployed lfor controlling the Circuit i of 'the carriage ;feer motor so that the knife Carriage cannot be moved thereby in elther direction so long as it is connected Vthrough the gear mechanism' with the main drive shaft 31.

The returnwire 7,4 .for the (logging spin-die motor 36 is connected tothe Circuit brealer switch 61. A Wire 85 is connected to the circuit breaker switcht6l and to a 'terminal' of inV'and .out? buttonsof the push button switch 52 and as long as the clutch 54 is in engagement withthe Circuit breaker. switch' 61', the motor 50 Can be actuated by depressing breaker, the Circuit is openedand the motor cannot be actuatedby either of the push buttons` of the switch, 52.` V

' The structure described above is old inthe ice i' art, and forms no part of the. present inven-V V tion other than in combination with'the structure now to be'described. p

' According tothe present invention method and means aregprovlded for moving.,the'v spindle rapidly into engagement Vwith the Vlofi'g'vt`V decreasing Vthe speed of vsuch'movenic-:nt proportion to the resistance of .the log, and' ceasing when the log offers a maximum resistance to' suchmovement. For this purpose the motor 36 is an-induction motor of the 'squirrel cage type having a high torque rotor which. develops its greatestV torque at standstill. The torque speed characteristic of this rotor is illustrated in Big. 3 by-a solidline ,incom-f parison tothat of a semi-hightorque rotor shown -bya dot and dash.line,and a standard rotor shown by a dotted line. From these curves it willv be noted that with the standard motor greatest torque -isdeveloped at about 75% speed and that atstandstillethe torque is less than half the'maximum. YVi'th the Semi-high torque rotor maximum Vtorqne is developed at about' 30% speed while at standstill the torque is little over half vthe maximum. Withthe high torque rotor the highest torque is developed at standstill and decreases as the speed increases. I i

The characteristic ofthe motor 3G is therefore such that if the switch 38 is held connected until the motor stalls, its greatest torque has been exerted in moving the spindle 13 to thrust its associated Chuck into the end of the log. I TWhen the switch 38 is operated' reversely, the same maximum torque is del veloped in order to remove the Chuck from the log. As an additional advantage, the amount of current used by the motor is such that the tor-'que per ampere at standstill z. is about twice as great as for` the standard motor, and about semi-high torque motor.

The motor 36 is quicl; acting, and yet sufficiently powerful to dog the log tight enough for Cutting, thus avoiding' the disadvantages of the friction drive. As the motor has a predetermined maximum torque, each log is dogged With eXactly the same pressurefor spindle greater than for the thrust. This does away with eXcessive loads on thethrust bearlngs, avoiding frequent renewal thereof, and avoiding excessive strains Vhile one embodiment of the invention has been disclosed in detail, the broad idea of the invention is not limited thereto, but includes such embodiments as fall Within the scope of thesubjoined claims.

Havingfthus described my invention, what Iclaim is: z f

1. In a veneer lathe, means adapted to be moved into engagement with the end of a log, and means for thrusting said means into engagement with a log, includuing 'a rotary drive means having an inherent maxlmum torque characteristic for driving said thrust-v ing means.

adapted to bemoved into engagemeilt with the opposite end of the log for 'securing the same` o between the spindles, anda positive. driving means having an inherentflmaximum thrust o to support the log therebetween, and driving means for actuating said dogging spindle toi Ward said tail spindle and adapted to'stop automatically after a predetermined actuation.

ly supporting said spindles, andautomatic driving means for actuating said dogging exerted thereby upon the end of the log.

signature.

In testimony whereof, I hereunto afix my 4 V8. In a veneer lathe, a tail spindle and a; dogglng spindle respectively adapted 'to en-` gage the ends of a log, means for respective ,spindle until a predetermined thrust has been ioo f` 2. In a veneer lathe, means ad'apted to be moved into engagement with a log, and means for so movmg sald means ineludlng a motor having its greatest torque at standstill for driving said moving means. V

3. In a veneer lathe, means adapted, to be moved into engagement with a log, vand means for so'moving said means, including an induction motor which develops its greatest torque when the motor stalls for driving said Vmoving means.

4;. In a veneer lathe, means adaptedto'be moved into engagement with a log, and means for so moving` said means, lncluding a squirrel cage motor having a high torque rotor for I driving said moving means. V

5. In a veneer lathe, means adapted to. be

moved into engagement with a log, and lmeans for so moving said means, including a motor -iaep' 

